Telephone system.



F. M. SLOUGH.

TELEPHONE SYSTEM.-

APPLICATI ON FILED MAY 15. I915.

IN VEN TOR.

FRANK M. SLOUGH, 0F ELYRIA,

STBOMBERG-CABLSON TELEPHONE MFG.

PORATION OF NEW YORK.

01110, ASSIGNOR, BY ivrnsnn asslonmnn'rs, To

(10., OF ROCHESTER, NEW YORK, A. COR- TELEPHONE SYSTEM.

Specification of Letters Patent.

' Patented Apr. 9, 1918..

Application filed May 15, 1915. Serial No. 28,251.

To all whom z't'may concern: I

Be it known that I, FRANK M. SLoUoH, a citizen of the United States, residing at Elyria, in the county of Lorain and State of Uhio, have invented certain new and useful Improvements in Telephone Systems; and 1 do hereby declare the following to be a full, clear, and exact description of the invention such as will enable others skilled in the artto which it appertains to make and use the same.

My invention relates to telephone systems and has for its objects the improvements in a number of ways or" the systems now in use, with the general aim of expediting or speeding up the service.

@ne of the objects of my invention is to provide improved means for interrupting the telephone line connecting links when the conversation is completed in order to release certain of the apparatus in the system for immediate use.

Another object of my invention is to provide means for enabling the operator to ring a called subscriber either when the calling subscriber is on the calling line, or when there is no connection to the calling line, at the same time providing means for preventing the ringing of the called subscriber when connection is made to the calling line,

but no subscriber is on the calling line.

Another object of my invention is to provide improved means for apprising the. called subscriber of the fact that the ringing of the called subscriber is taking place.

These and other objects of my invention will be understood from a description of a particular embodiment of the same.

The drawing shows diagrammatically a particular embodiment of a telephone system involving my invention. 1 p

I will first describe in a general way the apparatus shown in the drawing and its operation, and will then give a particular description thereof.

At .A is shown a telephone line whidh will be referred to hereafter as the calling line. At B is shown a substation on the line A, which will hereafter be called the calling subscriber, or the calling subscribers substation. At C is shown the main or central station of the system which is equipped inafter be spoken of as the called substation or the called subscriber. It will be understood that any suitable number of stations may be connected to either of the lines A and E.

Means are provided for connecting the link conductors to the telephone lines, here shown as switching means H and G. The switching means H will be spoken of hereafter as the answering switch and the means G as the calling switch. In the form shown the switching means consist of plugs and jacks, the line A being provided with multiple jacks J, J and J and the line E being provided with jacks J J and J The cord is provided with a plug P to cooperate with any one of the jacks of the calling line and with a cord? to cooperate with any of the jacks of the called line. The operators set is indicated at 'K, the ringing keys at L, the master key at M and the ringing machine at N. Portions of a second cord are indicated at D provided with plugs P and P Registers are indicated at O and 0 A busy tone apparatus is shown at Q.

When the calling subscriber desires a connection, the central station is signaled through the operation of the usual line relay and line lamp placed before the operators', one of whom responds in the usual way, by operating the switching means H by inserting the plug T into one of the jacks, say the jack J. The relay R will be operated over a circuit includingthe relay R, the resistance Z and the cut-off relay R If, however, ,prior to the closing of the switching device H,- the switching device H shall have been operated by another operator who thus captures the call, the relay R will not operate because most of the current which would otherwise flow through the relay R will be traversing a circuit intacts in the circuit of the secret listening relay 3-,. The relay R will also open contacts in' the circuit connections of the magnet R, as will be later explained.

When the strand 2is completed, the relay R, will be operated over a circuit including the line A, in a manner well understood, completing the circuit of the relay 3,, WlllCll I will be energized, completmg a circuit of the magnet X and causing the operation of the register 0. The relay R, will also connect the operators set K to the cord, so that the operator can now communicate w1th the subscriber at B. Learning that it is the subscriber at F that is desired, the line E-may be tested in the usual manner, or the operator may plug in' without the usual delay due to such testing. A circuit will be completed through the magnets R and B,. If the line E is busy, that is, if the switching device G,, for example, has been operated, there will have been completed about the circuit of the relays R and R a shunt including the relays R and R The relays R and R,"are so proportioned and arranged that under these circumstances the relay B which is high Wound and very sensitive, W111 be operated, but the relay R, will not. When R is thus operated, the relay R being shortcircuited by the relay R, for a suflicient length of time, will complete the special test circuit forv the operator. Assuming, however, that the line' was idle when the switching device G was operated, the relay R Wlll be operated and'the relay R, will not be operated sufiiciently long to cause the release of the relay R The relay R will break the circuit of the relay R disconnecting the operator from the cord. The operator then operates a ringing key to connect the source of ringing current to the called line. The closing of the key M completes the circuit through the ringing relay R which immediately locks itself independently of the key. The closing of the key M also completes a circuit through the relay Y, which is immediately made independent of the master key by the ringing relay. The ringing then 1 takes place over a circuit including the relay R A branch of this'circuit is completed through the strand 3 of the cord circuit and the calling line, through which a fraction of the current will course, indicatin to. the

' calling subscriber that the ringing is taking place.

When the called subscriber responds, the relay R, will cause the disconnection of the ringing current from the line, in a manner which will be explained in detail later, and the relay R will be energized. The breaking of the ringing circuit and the circuit of the ringing relay also interrupts the .circuit of the relay Y. With the apparatus in'this condition, the conversation takes place and at the close of the conversation, the subscriber at B hangs up, breaking the circuit of the relay R, and causing the energization of the relay R which interrupts the circuit of the relay R at 26, which then interrupts the strand 2, disconnecting the switching device H from the cord circuit.

When the operator withdraws the plugs, the system is restored to normal.

A detailed description of the operation is as followszWhen the subscriber at B takes the receiver 4 off of the hook 5, the latter being spring pressed upward, will close a switch 6 in the line'A. This will complete a circuit through the relay, 7, as follows: ground 8, battery 9 relay 7- switch 10- conductor 1.1 switch 6 conductor 12-. switch 13 to ground at 14:, causing the actuation of the 'rela 7 which closes a switch 15 in the circuit 0 the line lamps 16, 16 and 16 which will be lighted in multiple over the following circuits: 891517 to ground at 18. The lamps will be at Various positions at the main station, and one of the operators will' answer the call. In this case, we will assume that the operator who has charge of the cord D inserts the plug P into the jack J, thereby connecting the cord to the line. The contacts 19, 20 and 21 of the cord will register respectively with the contacts 22, 23 and 24 of the jack. The

following circuit will immediately be completed: ground 14cutoif relay R,-conductor 25-contact 24-contact' 21-switch device 26conductor 27resistance Zrelay R-battery 28'to ground 29. The relay R, will be energized, disconnecting the line lamp and line relay from the line by'opening the switches 10 and 13. The relay R will beenergized opening a switch 30 for a purpose to be'described, closing a switch 31 in the circuit of the relay R, and closing a switch 32, thereby completing a shunt 34 iabout the resistance device Z, and making the circuit of the relayR independent of means pleting that strand. As soon as the switch 33 is closed, a circuit is closed for the relay R as follows: ground 35upper winding of R conductor 36-2-3319-22126- 11232O37338lower winding of relay R battery W-to ground 39. The

'relay R opens the switch 40 and closes the switches ll and 42. A circuit is now completed for the relay R as follows: ground 44:switch 3lconductor 45R,conductor 46switch 42--conductor l7switch 48conductor 4:9-conductor- 50 W39. The relay R closes a switch 51, completing a circuit through the device X as follows:

Assuming that the subscriber desired is the subscriber at F, the operator operates the device G by inserting the plug P into the jack J Assuming that the line E is busy; that is, that a cord is already connected thereto, for example, that the cord at D is connected to the line E by the presence of the plug P in the jack J a circuit will then be completed as follows: 585960 R ground 61. Now, if the switching device G is operated, the current flow through the relay R will not be suflicient to cause the actuation of the same, owing to the shunt thereof through the relay R The characteristics of the relay R however, are such that it will be operated by the slight flow of current passing through the branch containing the relay R even when the branch containing the relay R diverts most of the current therefrom. Relay R being energized, closes a switch 62 shunting the relay R which lets go its armature, closing a switch 63. The operator will then get a special busy tone from the device Q through the conductor 64 and her receiver 65, which will indicate to her that the line is busy, when she will withdraw her plug P Assuming, however, that the line E is idle, the operation of the device Gr will complete a circuit for the relay R as follows: ground 5859-69conductor -R,conductor 71switch 72relay R 495OW39. R willbe energized, completing an alternate Circuit for itself and excluding therefrom the relay R This alternate circuit will be as follows: 5859697O72R and as be-- fore. Relay R opens the switch 48 in the circuit ofthe relays X and R completing the operation of the register, and causing the disconnection of the operators set from the cord. A switch 73 is also closed for a purpose to be described.

The subscriber at F is now rung, by operating one of the ringing keys, say the keys L and M. When the key M is operated, the following circuit is completed: 75M-78- R,-79-Yswitch 80conductor 8l.- :l-f

73t9 -5OW and 39. This is the circuit that is completed when the plug P is in the jack J and the subscriber is on the line. it, however, the plug P is in the jack J and the ubscriber is not on the line, this circuit will not be completed, because the circuit of the relay R would have been interrupted at the substation B, and the said relay deenergized, causing an interruption of the circuit of the relay R which has been described. This is of especial use, because frequently the subscriber F does not respond, and after waiting a reasonable length of time, the subscriber at B suspects that F will not respond, and retires. Under these circumstances the automatic ringing will be in- Y.

terrupted. An alternate path i provided for this circuit to enable the operator to ring tlfe subscriber F independently of any connection to a calling line, for example, when it is desired to call F in the morning, or call him to communicate with him for some other reason. Assuming, therefore, that the plug P has not been inserted into the jack J, the circuit of the rela 75M-78R 9Y8085switch 30-conductor 86switch 7 349-50\/V- 39. When relay R, has been energized, a switch 90 is operated, completing a locking circuit for the relay R which is independent of the key M, so that no matter how often the key M is now operated, neither the relays R nor Y will be affected, thus enabling the operator to use the key M for other purposes. The relay R will interrupt the close switches 92 and 93 in the ringing circuit, which will be as follows: ground 93 source of ringing current Nolf and on through the commutator 9%L-conductor 95switch 92through the switching device Gover the line Eback through the switching device G, the main" part of the current through the switch 93resistance device 96booster .9750Wto 39. If the link is connected to a calling line, a portion of this circuit will pass through a multiple of the device 96, 97 and W as follows: conductor 3the switching device H the calling linethe subscriber set Bto ground at 35 through conductor 36and the upper coil of the rela R The flow of current through this mu tiple will indicate to the calling subscriber that the ringing is going on and appease his impatience during the time necessary to secure theattenti'on ofthe subscriber F. As soon as subscriber F responds, the flow of current through the relay R, will be such that this relay will be operated, closing a switch 100 and completing a shunt of the relay R thereby diverting the current from the relay R which Will R, will be as follows:

ground be deenergized, releasing it armatures and restorin the switches controlled thereby to the con ition illustra ed in the drawing.

When the ,rela Y was operated, it closed a switch 101 in t e circuit of the register The response of the'calling subscriber and the closing of the switch 91 will complete a circuit through the relay R as follows:

ground 102winding;103-co'nductor 2-.

91-through the switching device .G and over the line E and the substation. circuit 1 at F t hr01.1gh. the switch 93conductor terrupts the strand 3 at 37, completes a 106k&

described, it provide a key s, which in addi- 104-winding v105battery W-ground 39. The rela R opens the switch 80in the circuit of .t e relay Y and causes the-completion of the actuation of the register. With the apparatus in this condition, the conversation takes place, and at the termination of the conversation, or as soon as the subscriber B han up, the circuit of the relay R will be bro en, thereby completing a circuit for the relayR- as follows: 44=-31-R -11 0*- 7349-50W39. The relay B ining circuit for itself by closing a switch 111,

and interrupts the circuit of the relay R at.

26. The relay Rv will then release the switches controlled by it, interrupting the strand 2 at 33. The operator may then withdraw the plugs from the jacks and the system will then be restored to normal.

In connection with the'system as before tion to enabling the operator to manually connect her telephone set to the cord circuit at any desired time, also containsinner contacts which ;are closed when the key is o erated and which are in the circuit inclu ing the calling subscribers telephone set and a winding ofthe relay R and therefore, when the key is operated, provided the callin subscriber'is on the line, the relay R, will a so be operated, closing the circuitof the disconnect relayR in case the disconnection of the answering end of the cord haspreviously occurred, and re-connecting the subscribers line wires to the talking nection with the cord circuit by the operating of the key S, which brings the cord circuit into the same condition as in answering the previous call. If the subscriber desires a connection with the same line as beparatus means is operated and the substation bridge fore,-a1l that will be necessary will be for the operator to again depress the proper ringing key as before and to restore her listening key S. If connection with, another line is de sired, the plugP will be withdrawn from the jack J and connected to a jack of the line desired, whereupon the ringing will take place upon the depressal of key, as before described.

the proper ringing illustrated this embodiment of my I have invention and the details shown therein for the purpose of describing the invention, and not that I wish to be limited to this articular form or to the details shown, since it will be apparent to those skilled in the art that many departures may be made from such form and details, without departing from the spirit of the invention.

I claim 1 1. In a telephone system, the combination of a calling line, a substation on said line, a called line, a substation on said line, a signal, at the substation, a main station, means at" the main station including link conduc-.

tors for connecting said lines together,

switching means for connecting the link conductors to the called line and switching means for connecting the link conductors to the calling line, ringing apparatus at the main station for operating the signal at the substation, controlling means for said ringing apparatus controlling the connection of the same to the signal, including a circuit, mechanism under the control of.-thecalling subscriber and said switching means for connecting the link conductors -to the calling line governing said circuit, means independent of said calling subscriber and said switching means controlling said circuit, and apparatus to supersede said last .namedmeans and deprive said last named means of such control of said circuit.

2. In a telephone system, the combination of a calling line, a substationon saidline including a talking bridge, a called line, a substation on said line including a signal, a main station, means at the main station for connecting said lines'together including link conductors and switching means for connecting the link conductors to the calling line, apparatus for operating the-signal at the stationon the called line, mechanism for rendering said apparatus automatical1 operative when said switchin means is 'u operated, mechanism for ten ering said apoperative when .said' switching is closed, said apparatus being inoperative when the switching means is operated "and the substation bridge is open. Y

3. In a telephone system, the combination of a calling line, a substation on said line including a talking bridge, a called line,

substation apparatus on said line including a signal, means 'atthe main station including link conductors and a switch for conparatus to the called line, a circuit for said relay, means to close said circuit when said.

switch is operated and the substation bridge is closed, means to opensaid circuit and render inoperative the signaling apparatus when said'switch is closed and the substation bridge is open, a normally closed branch of said circuit and means for closing said branch and rendering said signaling apparatus operative when said switch is open.

4. In a telephone system, the COIIlblIliLtlbIl of a calling line, a substation on said line including a talking bridge, a called line, a substation on said line including a signal, a

main station, means at themain station for connecting said lines together including link conductors and a switch for connecting the link conductors to the calling line, apparatus at the main station foroperating the signal at the substation on the called line, means for connecting said apparatus to said signal, including a relay, circuit connections for said relay, means controlling said connections for completing a circuit for said relay when said switch is operated and the substation bridge on the calling line is completed, means to interrupt the circuit of said relay when the switch 1s operated and the substation bridge is broken, and normally closed means controlling said circuit connections for completing a circuit through said relay whensaid switch is unoperated.

5. In a telephone system, the combinarendering said signal. apparatus operative when the link conductors are disconnected. from the calling line.

6. In a telephone system, a calling line, substation apparatus on said line including a talking bridge, a called line, substation apparatus on said line including a signal, a

main station, a cord circuit at the main station for connecting the lines together, an answering switch for connecting the cord to the calling line, a calling switch for connecting the cord circuit to the called line, a

answering switch and the substation bridge source of ringing current at the main station, conductors for connecting the source to the called line, a relay controlling said conductors, a circuit for said relay, means for completing said circuit including the on the calling line, means for breaking said circuit, including the substation bridge on thecalling line, a branch of said circuit and a relay for completing said branch when. the answering switch is open. I

7. In a telephone system, the combination of a calling line, substation apparatus in cluding a hook-switch on the calling line,

a called line, substation apparatus includso ing a signal on the called line, a main sta- A tion, a cord circuit at the main station, an answering switch for connecting the cord to the calling line, a callin switch for connecting the cord to a ca led line, a source of signaling current for" causing the actuation of the signal on the called line, conductors for connecting said source to the called line, a relay controlling said conductors, .a circuit for said relay, contacts in said circuit, a second relay controlling said contacts, a circuit for said second relay in cluding the contacts of the answering switch and of the hook-switch, a branch of the circuit of the first named relay and electromagnetic means for closing said branch when said'answering switch is in open position.

8. In a telephone system, the combination of telephone lines, a three-strand link con- 10d nector for connecting the lines together, including two talking strands, a pair ofrelays, one controlling one of said talking strands and the other controlling the other of said talking strands, a circuit for one of said relays including a part of the third strand and means including a portion of the third strand for causing the actuation of said relays to interrupt the talking strands.

9. In a telephone system, the combination of telephone lines, means for connecting said lines together, including plugs and jacks and a pair of talking strands, apparatus for automatically interrupting said strands when the conversation is completed, including a pair of relays, each of said relays controlling one of said talking strands only and means including one of said relays controlling the other of said relays.

10. In a telephone system, the combina- 7 tion of telephone lines, means for connecting said lines together, including plugs and jacks and ,a pair of talking strands, means for automatically interrupting said strands when the conversation is completed, includin a pair of relays, each of said relays controlling a talking strand and each of said relays controlling the other of said relays.

11. In a telephone system, the combinas tion of a called line and a calling line, means 'for connecting said lines together, including plugs and jacks and a pair of talking strands, a relay controlling each of said strands, and a circuit for eachof said relays controlledby the otherof said relays.

12; In a telephone system, the combination of a called line, substation apparatus on said line, a main station, a telephone jackat said main station associated with said called line, a cord circuit, a calling plug connected to said cord circuit and adapted for insertion into the jack of the called line,

a sensitive relay and aless sensitive relay in a circuit including a source of current,

contacting terminals of said plug and jack, 15

and a relay associated with said line circuit said sensitive relay adapted when operated I to cause the operation of a busy signal, said less sensitive relay When operated, adapted FRANK M. SLOUGH. 

